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The kidney sessions of the 2017 Banff Conference focused on 2 areas: clinical implications of inflammation in areas of interstitial fibrosis and tubular atrophy (i‐IFTA) and its relationship to T cell–mediated rejection (TCMR), and the continued evolution of molecular diagnostics, particularly in the diagnosis of antibody‐mediated rejection (ABMR). In confirmation of previous studies, it was independently demonstrated by 2 groups that i‐IFTAis associated with reduced graft survival. Furthermore, these groups presented that i‐IFTA, particularly when involving >25% of sclerotic cortex in association with tubulitis, is often a sequela of acute TCMRin association with underimmunosuppression. The classification was thus revised to include moderate i‐IFTAplus moderate or severe tubulitis as diagnostic of chronic active TCMR. Other studies demonstrated that certain molecular classifiers improve diagnosis of ABMRbeyond what is possible with histology, C4d, and detection of donor‐specific antibodies (DSAs) and that both C4d and validated molecular assays can serve as potential alternatives and/or complements to DSAsin the diagnosis of ABMR. The Banff ABMRcriteria are thus updated to include these alternatives. Finally, the present report paves the way for the Banff scheme to be part of an integrative approach for defining surrogate endpoints in next‐generation clinical trials. The Banff consortium presents revisions to the diagnostic criteria for T cell– and antibody‐mediated kidney transplant rejection, including specific criteria for chronic active T cell–mediated rejection, plus prospects for integrative endpoints in clinical trials. See related articles on pages 321, 364, and 377.

The kidney sessions of the 2017 Banff Conference focused on 2 areas: clinical implications of inflammation in areas of interstitial fibrosis and tubular atrophy (i-IFTA) and its relationship to T cell–mediated rejection (TCMR), and the continued evolution of molecular diagnostics, particularly in the diagnosis of antibody-mediated rejection (ABMR). In confirmation of previous studies, it was independently demonstrated by 2 groups that i-IFTA is associated with reduced graft survival. Furthermore, these groups presented that i-IFTA, particularly when involving >25% of sclerotic cortex in association with tubulitis, is often a sequela of acute TCMR in association with underimmunosuppression. The classification was thus revised to include moderate i-IFTA plus moderate or severe tubulitis as diagnostic of chronic active TCMR. Other studies demonstrated that certain molecular classifiers improve diagnosis of ABMR beyond what is possible with histology, C4d, and detection of donor-specific antibodies (DSAs) and that both C4d and validated molecular assays can serve as potential alternatives and/or complements to DSAs in the diagnosis of ABMR. The Banff ABMR criteria are thus updated to include these alternatives. Finally, the present report paves the way for the Banff scheme to be part of an integrative approach for defining surrogate endpoints in next-generation clinical trials.

The authors conducted a prospective trial to assess the feasibility of real time central molecular assessment of kidney transplant biopsy samples from 10 North American or European centers. Biopsy samples taken 1 day to 34 years posttransplantation were stabilized in RNAlater, sent via courier overnight at ambient temperature to the central laboratory, and processed (29 h workflow) using microarrays to assess T cell– and antibody-mediated rejection (TCMR and ABMR, respectively). Of 538 biopsy samples submitted, 519 (96%) were sufficient for microarray analysis (average length, 3 mm). Automated reports were generated without knowledge of histology and HLA antibody, with diagnoses assigned based on Molecular Microscope Diagnostic System (MMDx) classifier algorithms and signed out by one observer. Agreement between MMDx and histology (balanced accuracy) was 77% for TCMR, 77% for ABMR, and 76% for no rejection. A classification tree derived to provide automated sign-outs predicted the observer sign-outs with >90% accuracy. In 451 biopsy samples where feedback was obtained, clinicians indicated that MMDx more frequently agreed with clinical judgment (87%) than did histology (80%) (p = 0.0042). In 81% of feedback forms, clinicians reported that MMDx increased confidence in management compared with conventional assessment alone. The authors conclude that real time central molecular assessment is feasible and offers a useful new dimension in biopsy interpretation. ClinicalTrials.gov NCT#01299168.

The authors conducted a prospective trial to assess the feasibility of real time central molecular assessment of kidney transplant biopsy samples from 10 North American or European centers. Biopsy samples taken 1 day to 34 years posttransplantation were stabilized in RNAlater, sent via courier overnight at ambient temperature to the central laboratory, and processed (29 h workflow) using microarrays to assess T cell– and antibody‐mediated rejection (TCMRand ABMR, respectively). Of 538 biopsy samples submitted, 519 (96%) were sufficient for microarray analysis (average length, 3 mm). Automated reports were generated without knowledge of histology and HLAantibody, with diagnoses assigned based on Molecular Microscope Diagnostic System (MMDx) classifier algorithms and signed out by one observer. Agreement between MMDx and histology (balanced accuracy) was 77% for TCMR,77% for ABMR, and 76% for no rejection. A classification tree derived to provide automated sign‐outs predicted the observer sign‐outs with >90% accuracy. In 451 biopsy samples where feedback was obtained, clinicians indicated that MMDx more frequently agreed with clinical judgment (87%) than did histology (80%) (p = 0.0042). In 81% of feedback forms, clinicians reported that MMDx increased confidence in management compared with conventional assessment alone. The authors conclude that real time central molecular assessment is feasible and offers a useful new dimension in biopsy interpretation. ClinicalTrials.gov NCT#01299168. An international trial to study the feasibility and effectiveness of real‐time central microarray processing of kidney transplant biopsies, interpreted by the Molecular Microscope Diagnostic System, finds that 96% of all biopsies received could be reported, and participating clinicians indicate considerable potential of this method to change care.

The XIIIBanff meeting, held in conjunction the Canadian Society of Transplantation in Vancouver, Canada, reviewed the clinical impact of updates of C4d‐negative antibody‐mediated rejection (ABMR) from the 2013 meeting, reports from active Banff Working Groups, the relationships of donor‐specific antibody tests (anti‐HLAand non‐HLA) with transplant histopathology, and questions of molecular transplant diagnostics. The use of transcriptome gene sets, their resultant diagnostic classifiers, or common key genes to supplement the diagnosis and classification of rejection requires further consensus agreement and validation in biopsies. Newly introduced concepts include the i‐IFTAscore, comprising inflammation within areas of fibrosis and atrophy and acceptance of transplant arteriolopathy within the descriptions of chronic active T cell–mediated rejection (TCMR) or chronic ABMR. The pattern of mixed TCMRand ABMRwas increasingly recognized. This report also includes improved definitions of TCMRand ABMRin pancreas transplants with specification of vascular lesions and prospects for defining a vascularized composite allograft rejection classification. The goal of the Banff process is ongoing integration of advances in histologic, serologic, and molecular diagnostic techniques to produce a consensus‐based reporting system that offers precise composite scores, accurate routine diagnostics, and applicability to next‐generation clinical trials. In this article, the Banff consortium presents the most updated version of the kidney, pancreas, and VCA transplant rejection classification and prospects for implementing intragraft molecular assessment. See the companion report on page 42.

The XIII Banff meeting, held in conjunction the Canadian Society of Transplantation in Vancouver, Canada, reviewed the clinical impact of updates of C4d-negative antibody-mediated rejection (ABMR) from the 2013 meeting, reports from active Banff Working Groups, the relationships of donor-specific antibody tests (anti-HLA and non-HLA) with transplant histopathology, and questions of molecular transplant diagnostics. The use of transcriptome gene sets, their resultant diagnostic classifiers, or common key genes to supplement the diagnosis and classification of rejection requires further consensus agreement and validation in biopsies. Newly introduced concepts include the i-IFTA score, comprising inflammation within areas of fibrosis and atrophy and acceptance of transplant arteriolopathy within the descriptions of chronic active T cell–mediated rejection (TCMR) or chronic ABMR. The pattern of mixed TCMR and ABMR was increasingly recognized. This report also includes improved definitions of TCMR and ABMR in pancreas transplants with specification of vascular lesions and prospects for defining a vascularized composite allograft rejection classification. The goal of the Banff process is ongoing integration of advances in histologic, serologic, and molecular diagnostic techniques to produce a consensus-based reporting system that offers precise composite scores, accurate routine diagnostics, and applicability to next-generation clinical trials.

El trasplante es una modalidad de tratamiento óptima para la enfermedad renal crónica avanzada, que requiere de por vida la adherencia al tratamiento inmunosupresor. El objetivo de este estudio fue evaluar la adherencia al tratamiento después de un trasplante renal. Además de analizar el grado de información recibida al mes y 18 meses postrasplante y valorar su influencia en la adherencia al tratamiento.

Analizar y evaluar nuestra experiencia en el tratamiento quirúrgico mediante abordaje abierto de las estenosis ureterales complejas postrasplante renal de adulto en un centro de tercer nivel en los últimos 7 años. Se revisan las diferentes alternativas quirúrgicas utilizadas.

The 10th Banff Conference on Allograft Pathology was held in Banff, Canada from August 9 to 14, 2009. A total of 263 transplant clinicians, pathologists, surgeons, immunologists and researchers discussed several aspects of solid organ transplants with a special focus on antibody mediated graft injury. The willingness of the Banff process to adapt continuously in response to new research and improve potential weaknesses, led to the implementation of six working groups on the following areas: isolated v‐lesion, fibrosis scoring, glomerular lesions, molecular pathology, polyomavirus nephropathy and quality assurance. Banff working groups will conduct multicenter trials to evaluate the clinical relevance, practical feasibility and reproducibility of potential changes to the Banff classification. There were also sessions on quality improvement in biopsy reading and utilization of virtual microscopy for maintaining competence in transplant biopsy interpretation. In addition, compelling molecular research data led to the discussion of incorporation of omics‐technologies and discovery of new tissue markers with the goal of combining histopathology and molecular parameters within the Banff working classification in the near future.

The 10th Banff Conference on Allograft Pathology was held in Banff, Canada from August 9 to 14, 2009. A total of 263 transplant clinicians, pathologists, surgeons, immunologists and researchers discussed several aspects of solid organ transplants with a special focus on antibody mediated graft injury. The willingness of the Banff process to adapt continuously in response to new research and improve potential weaknesses, led to the implementation of six working groups on the following areas: isolated v-lesion, fibrosis scoring, glomerular lesions, molecular pathology, polyomavirus nephropathy and quality assurance. Banff working groups will conduct multicenter trials to evaluate the clinical relevance, practical feasibility and reproducibility of potential changes to the Banff classification. There were also sessions on quality improvement in biopsy reading and utilization of virtual microscopy for maintaining competence in transplant biopsy interpretation. In addition, compelling molecular research data led to the discussion of incorporation of omics-technologies and discovery of new tissue markers with the goal of combining histopathology and molecular parameters within the Banff working classification in the near future.

The 9th Banff Conference on Allograft Pathology was held in La Coruna, Spain on June 23-29, 2007. A total of 235 pathologists, clinicians and scientists met to address unsolved issues in transplantation and adapt the Banff schema for renal allograft rejection in response to emerging data and technologies. The outcome of the consensus discussions on renal pathology is provided in this article. Major updates from the 2007 Banff Conference were: inclusion of peritubular capillaritis grading, C4d scoring, interpretation of C4d deposition without morphological evidence of active rejection, application of the Banff criteria to zero-time and protocol biopsies and introduction of a new scoring for total interstitial inflammation (ti-score). In addition, emerging research data led to the establishment of collaborative working groups addressing issues like isolated 'v' lesion and incorporation of omics-technologies, paving the way for future combination of graft biopsy and molecular parameters within the Banff process.

The 9th Banff Conference on Allograft Pathology was held in La Coruna, Spain on June 23–29, 2007. A total of 235 pathologists, clinicians and scientists met to address unsolved issues in transplantation and adapt the Banff schema for renal allograft rejection in response to emerging data and technologies. The outcome of the consensus discussions on renal pathology is provided in this article. Major updates from the 2007 Banff Conference were: inclusion of peritubular capillaritis grading, C4d scoring, interpretation of C4d deposition without morphological evidence of active rejection, application of the Banff criteria to zero-time and protocol biopsies and introduction of a new scoring for total interstitial inflammation (ti-score). In addition, emerging research data led to the establishment of collaborative working groups addressing issues like isolated ‘v’ lesion and incorporation of omics-technologies, paving the way for future combination of graft biopsy and molecular parameters within the Banff process.

Patients with a protocol renal allograft biopsy simultaneously displaying interstitial fibrosistubular atrophy (IFTA) and subclinical rejection (SCR) have a shortened graft survival than patients with a normal biopsy, or with a biopsy only displaying IFTA or SCR. The poor outcome of these patients could be related with a more severe inflammation. We evaluate the immunophenotype of infiltrating cells in these diagnostic categories. Nonexhausted paraffin blocks from protocol biopsies done during the first year were stained with anti-CD45, CD3, CD20, CD68 and CD15 monoclonal antibodies. Glomerular and interstitial positive cells were counted. C4d deposition in peritubular capillaries was evaluated. Histological diagnoses were: normal (n 80), SCR (n 17), IFTA (n 42) and IFTA SCR (n 17). Only interstitial CD20 positive cells were significantly increased in patients displaying IFTA SCR; normal (137 ± 117), SCR (202 ± 145), IFTA (208 ± 151) and IFTA SCR (307 ± 180 cellsmm2), p < 0.01. The proportion of biopsies displaying C4d deposition was not different among groups. The upper tertile of CD20 positive interstitial cells was associated with a decreased death-censored graft survival (relative risk: 3.01, 95 confidence interval: 1.23-7.35; p 0.015). These data suggest that B-cell interstitial infiltrates are associated with histological damage and outcome, but do not distinguish whether these infiltrates were the cause or the consequence of chronic tubulo-interstitial damage.

Patients with a protocol renal allograft biopsy simultaneously displaying interstitial fibrosis/tubular atrophy (IF/TA) and subclinical rejection (SCR) have a shortened graft survival than patients with a normal biopsy, or with a biopsy only displaying IF/TA or SCR. The poor outcome of these patients could be related with a more severe inflammation. We evaluate the immunophenotype of infiltrating cells in these diagnostic categories. Nonexhausted paraffin blocks from protocol biopsies done during the first year were stained with anti-CD45, CD3, CD20, CD68 and CD15 monoclonal antibodies. Glomerular and interstitial positive cells were counted. C4d deposition in peritubular capillaries was evaluated. Histological diagnoses were: normal (n = 80), SCR (n = 17), IF/TA (n = 42) and IF/TA + SCR (n = 17). Only interstitial CD20 positive cells were significantly increased in patients displaying IF/TA + SCR; normal (137 ± 117), SCR (202 ± 145), IF/TA (208 ± 151) and IF/TA + SCR (307 ± 180 cells/mm2), p < 0.01. The proportion of biopsies displaying C4d deposition was not different among groups. The upper tertile of CD20 positive interstitial cells was associated with a decreased death-censored graft survival (relative risk: 3.01, 95% confidence interval: 1.23–7.35; p = 0.015). These data suggest that B-cell interstitial infiltrates are associated with histological damage and outcome, but do not distinguish whether these infiltrates were the cause or the consequence of chronic tubulo-interstitial damage.

The 8th Banff Conference on Allograft Pathology was held in Edmonton, Canada, 15–21 July 2005. Major outcomes included the elimination of the non-specific term ‘chronic allograft nephropathy’ (CAN) from the Banff classification for kidney allograft pathology, and the recognition of the entity of chronic antibody-mediated rejection. Participation of B cells in allograft rejection and genomics markers of rejection were also major subjects addressed by the conference.

Abstract: This study is based on two commercially available YBCO thin films deposited by the thermal coevaporation method on different substrates (MgO and LaAlO3). Those films should be optimized for microwave applications. The structure and microstructure of the film deposited on LaAlO3 have been investigated, respectively by XRD and SEM. These characterizations showed the high quality of the films concerning the c-axis orientation and the smooth and homogenous morphology. The films have then been etched into two different coplanar line resonators by ionic method (YBCO/LaAlO3) and chemical one (YBCO/MgO) and their microwave properties have been characterized in two different cryogenic experimental set-ups. Despite the differences between these coplanar resonators, we have obtained the same intrinsic parameters (λ0 = 190 nm, T c=87 K with γ = 3) corresponding to the data provided by THEVA and a very low surface resistance (R s=0.4 m Ω at 31 K and 10 GHz).

An experimental observation of the improvement of the microwave properties of high temperature superconductor thin film subjected to a weak DC magnetic field is reported. This characterization was done with two YBCO films deposited onto LaAlO3substrates and the coplanar resonator technique was used to extract their microwave properties. The results are presented as a comparison between the behaviors of a sample that exhibits an unusual effect with another sample that has a usual behavior. To understand the origins of such a difference, the crystallographic properties and the microstructure were investigated respectively by mean of X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). A major difference in terms of growth axis orientation and of granularity has been observed between the two samples. Based on the correlated variation of the surface resistance and the surface reactance of the considered sample, the presence of anomalous weak links and also of a-axis grains in one of the films could explain its unusual behavior.

In renal transplantation the beneficial immunosuppressive effects of cyclosporin (CsA) may be curtailed by its nephrotoxicity, specially in patients receiving a cadaveric allograft from suboptimal donors or at risk of delayed graft function. Mycophenolate mofetil (MMF) and antithymocyte globulin (ATG) have each demonstrated to be potent immunosuppressants in renal transplantation. In a prospective analysis we have studied the results at 6 months of the combination of MMF, ATG and low-dose steroids in patients with low immunological risk receiving a first cadaveric renal allograft from a suboptimal donor or at risk of delayed graft function.

Hypertension is more severe in kidney transplant patients than in patients with chronic kidney disease (CKD) and similar renal function. The aim is to study the contribution of subclinical atherosclerosis and low grade inflammation to hypertension in kidney transplants.

Cyclosporin A (CsA) is a potent immunosuppressive drug whose effect is well known in the organ transplantation field. Treatment with CsA reduces the incidence of rejection and improves graft survival after renal transplantation (RT). However, to set against the clear advantages of CsA, a most important problem is nephrotoxicity [1, 3]. Scientists are therefore seeking new non‐nephro‐toxic Cs derivatives, but the search has not yet borne fruit. Teams working in organ transplantation attempt to avoid nephrotoxicity by switching to conventional treatment with azathioprine (AZA), starting 1, 3 or 6 months after transplantation [8, 11]. Conversion from CsA to AZA has not always been successful due to the high incidence of rejection [4]. AZA has also been started immediately after transplantation in combination with CsA at low doses [5], and in some instances no CsA is administered when oliguric acute tubular necrosis is present [10]. In a previous report [2], we presented the short‐term results of the treatment with a CsA—AZA combination, reducing the CsA dose and giving a moderate dose of AZA in 21 transplanted patients not achieving acceptable graft function. In the present study we analysed the long‐term results in a group of patients whose kidney biopsy examination results were compatible with CsA nephrotoxicity.

We have conducted an immunocytochemical analysis to investigate the presence of the recently described vascular cell adhesion molecule-1 (VCAM-1) in human kidney, using the anti-VCAM-1 monoclonal antibody 1.4C3. In normal control tissue VCAM-1 was present on some (but not all) parietal epithelial cells lining Bowmans capsule. Forty-nine of fifty clinical biopsy specimens were characterised by the additional presence of VCAM-1 on proximal tubular cells. This was most marked in biopsies of patients with interstitial nephritis or systemic vasculitis with crescentic nephritis, but was also observed in biopsies with minimal change, IgA or lupus nephropathy, or from patients with diabetic nephropathy, amyloid, or gout. Proximal tubule VCAM-1 correlated significantly with the number of transferrin-receptor-positive leukocytes (r = 0.607, P<0.0001) in the interstitium, but not with expression of HLA-DR by tubular cells. Surprisingly, VCAM-1 was not observed on vascular endothelial cells in these biopsies, even in the presence of a marked infiltrate; this contrasts with other tissues (e.g. skin and synovium). The presence of VCAM-1 on tubular cells in the inflamed kidney indicates the potential for these cells to interact with mononuclear cells, either as accessory cells or as cytotoxic targets. The unexpected absence of VCAM-1 in renal vascular endothelial cells suggests local differences in the endothelial cells of this organ.